Functionally Graded Materials: Continuous Casting and Forming of Electric Copper Conductors

Increasing electrification of technical products has been evident for some years. With regard to the demand for extended service life and increased performance, the technological potential of monolithic metals has been largely exhausted. For this reason, important academic and industrial activities have emerged that focus on the development of hybrid metal structures for electrical applications. Not only the fabrication of hybrid materials itself is a scientific and technological challenge. It also requires a cross-process understanding of the evolution of material properties and technological relationships. The aim of the project is the scientific investigation of the process route for the production of electrical copper conductors. In particular, the project focuses on the development of functionally graded materials with a metallurgical property profile locally adapted to the special requirements of electrical conductors. The process route of initial continuous casting, subsequent extrusion and final wire drawing represents an economical production sequence for the manufacture of copper conductors which exhibit excellent electrical conductivity on the one hand and comparatively high strength on the other. This complex property profile is generated by a material gradient across the cross-section of the metallic product. The transition from a pure copper base material in the peripheral region and a copper-zinc alloyed region in the interior of the product is continuous, which means that no macroscopic interfaces occur between the different material regions. In the present research project, a methodology for the resource-efficient fabrication of functionally graded materials is developed. The scientific approach is based on theoretical, experimental, and numerical techniques. The objective is challenging and the knowledge gained pushes the limits of what is currently technically possible.